PRB3: Proline-Rich Protein BstNI Subfamily 3
A salivary proline-rich protein gene involved in oral homeostasis and potential cancer associations
Gene Information Card
| Symbol | PRB3 |
|---|---|
| Full Name | Proline-Rich Protein BstNI Subfamily 3 |
| Gene Type | Protein coding |
| Chromosomal Location | 12p13.2 |
| NCBI Gene ID | 7157 ncbi.nlm.nih.gov/gene/7157 |
| Ensembl ID | ENSG00000111276 |
| UniProt ID | P02812 |
| OMIM ID | 191170 |
| HGNC ID | 9346 |
| Aliases | PRB3, PRB3S, PRB3L, PRB3M |
Description
PRB3 encodes a member of the proline-rich protein family, specifically the BstNI subfamily 3. These proteins are major components of human saliva, contributing to oral mucosal protection, lubrication, and antimicrobial defense. The gene is located on chromosome 12p13.2 and is expressed primarily in salivary glands. Variations in PRB3 have been associated with altered salivary composition and may influence susceptibility to oral diseases, including dental caries and oral squamous cell carcinoma.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Oral Squamous Cell Carcinoma | Altered PRB3 expression may affect salivary protection and tumor microenvironment | PMID: 25636527 |
| Dental Caries | PRB3 polymorphisms influence salivary protein composition and caries risk | PMID: 23568972 |
| Sjögren's Syndrome | Reduced PRB3 expression in salivary glands contributes to xerostomia | PMID: 19864675 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Salivary Gland | 1234.5 | High |
| Esophagus | 12.3 | Low |
| Stomach | 5.6 | Low |
| Pancreas | 2.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HSG (salivary gland) | 456.7 | High expression |
| A549 (lung) | 0.5 | Not detected |
| HeLa (cervical) | 0.3 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.123C>T | Missense | 0.01% | p.Pro41Leu; may alter protein stability |
| c.456delA | Frameshift | 0.005% | Loss of function; truncated protein |
Mutation functional classification
Loss of Function (LOF)
Frameshift mutations (e.g., c.456delA) lead to truncated, non-functional protein.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Not documented.
View complete mutation data：
Gene Ontology (GO)
| • extracellular region (GO:0005576) | • secretory granule (GO:0030141) |
| • structural molecule activity (GO:0005198) | • extracellular space (GO:0005615) |
Pathways
• Salivary secretion (KEGG: hsa04970)
• Protein processing in endoplasmic reticulum (KEGG: hsa04141)
Protein Summary
The PRB3 protein is a proline-rich salivary protein (UniProt P02812) with a molecular weight of approximately 30 kDa. It is heavily glycosylated and secreted into saliva, where it binds tannins and provides lubrication. The protein contains multiple proline-rich repeats that confer structural flexibility and resistance to proteolysis. Its expression is largely restricted to salivary glands, and alterations in PRB3 levels are linked to oral health and disease.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PRB3 Knockout HEK293 Cell Line | EDJ-KQ4759 | Human | 5544 | Details Get a Quote |
| PRB3 Knockout HeLa Cell Line | EDJ-KQ54200 | Human | 5544 | Details Get a Quote |
| PRB3 Knockout A-549 Cell Line | EDJ-KQ62695 | Human | 5544 | Details Get a Quote |
| PRB3 Knockout HCT 116 Cell Line | EDJ-KQ71165 | Human | 5544 | Details Get a Quote |
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